One great feature of my J3 is the eq settings. They make it possible to get a relatively neutral sound from headphones that otherwise has weaknesses. For instance too much bass response or too little mid register.

I have noticed that published eq settings seem to often only use positive adjustments. Perhaps even positive adjustments on all frequency bands. I think that is wierd. I try to use eq settings that are neutral regarding perceived volume, that only affects the overall tonal distribution.

To get more bass you can increase the lower frequencies. But you can also decrease the upper frequencies instead. I attempt to do both at the same time. The reason is that it means smaller adjustments, both up and down, and I assume less distortion. Also the risk of clipping is reduced.

One reason for raising all frequencies could be that you wish to increase the overall volume, and the normal volume adjustment is not enough. But I would assume that a normalisation of the media would have been better.

I have tested both types of normalisation and have to admit that I can't hear much difference. The differences I believe I have heard is definitely in favour of smaller changes both up and down, instead of only up. But that may be placebo.

How do you reason around eq? Do you try to boost everything in different amounts, or do you have a more balanced setting around zero with both boost and reductions to get the same result?

My opinion on that topic is the same as yours, I boost certain frequencies and reduce others. I can't give a proper explanation because I lack the necessary vocabulary, but I can definitely say that...
... I think that this way causes as little distortion/clipping as possible. (Just what you said in your post)
and
... it simply sounds the best to me. (I cannot describe the differences, it just sounds better IMO... might be a placebo of course)

the eq has big limits imo, im kinda disapointed by it although i see it as necessary.

the positives do introduce some clipping and other issues due to the clunky adjustment range. i find that issue is extended much further by the other effects such as mp and stereo enhance, its a really hard ballance to find.

i would live in the negatives as it really does provide a much more balanced sound.
but ...i need the volume boost for my phones that only the positives provide, atm my balanced setting is simply 01100, for more volume i go to 12211 or even 12210 if theres treble issues although i try to avoid any +'s if possible.

in my experience, with a loud track, some extra volume and the trebles tamed down you can still get the phones shaking on your ears but the bass sounds sooo much smoother in the negatives
having the bass at -2 sounds way better than +2 in that respect.

if you can use more volume over +values to get more bass, use the +\- to tune the dominance\tone (also lacking the correct words).

that trained up studio guy mentioned on here that it is the correct method for studio work and audio engineers to use negatives over positives, dropping the rest and raising the volume as required.

still considering an amp just to take advantage of this without the volume issue's.

I have noticed that published eq settings seem to often only use positive adjustments.

I think that's pretty much expected result. Subjectively louder almost always equals better. When you go from flat EQ to your boosting +10,+4,+1 etc EQ, the overall SPL level increases a few dB. Even though the tonal balance may in fact be worse than it was before, the added volume level makes up for it. (I no longer trust many subjective reviewer's takes on sound quality because even "experts" can easily mistakenly think they can do comparative listening without carefully eliminating volume level differences.)

Anyway, I haven't noticed much distortion when using Cowon's EQ. (Or is it Wolfson's EQ we are using in reality...) Except that I remember that having the EU volume cap active used to destroy the equalized sound on Cowon S9, but volume cap disabled things would be ok. They must use a healthy dose of digital headroom to make sure even boosting EQs won't clip.

The point about avoiding positive eq if possible is a good one. I seem to have room for that without problems using my headphones.

But I also agree that I have rarely heard any obvious distortion or clipping from moderate eq alone. In combination with mp or mach3bass it is more common.

To avoid the trap of louder is better, I try to make the eq settings as similar to flat in subjective volume as possible before comparing. Before I decide which setting is best I also compare settings by lowering the volume before switching, and then raising it to a "pleasant" level while listening.

My goal is to try to make the J3 and the headphones "disappear" so I no longer hear any tonal coloring of the sound but only the recording. Actually it seems that my ears are rather forgiving when I start to get close. So I try to approach the best settings from both directions and then average out to the middle. It is a continuing process for me. When I hear some distracting coloring due to tonal imbalance I make a small adjustment. I have one preset per headphone and two that I use to fork in. But I suspect that I sometimes adjust for tonal imbalances in the recording.

When listening using speakers a boost of bass require much higher effect than boost of treble. So it is easy to cause distortion that way. I am not sure if bass boost using headphones is as demanding? Or that could be a reason to keep the bass adjustment at 0 and only adjust in other bands?

My goal is to try to make the J3 and the headphones "disappear" so I no longer hear any tonal coloring of the sound but only the recording.

The keyword for realistic headphone sound is HRTF. But since every individual's HRTF is unique and thus different from everyone else's, its a tricky business to achieve even moderate level of audio transparency using headphones. Its quite disapponinting how little this field has developed in the recent years, even the best headphones are miles behind of loudspeaker-based playback IMO.

Dunno if you have seen this already, but it might be worth a look if you want a systematic method to try to improve the headphone sound: click.

Quote:

When listening using speakers a boost of bass require much higher effect than boost of treble. So it is easy to cause distortion that way. I am not sure if bass boost using headphones is as demanding?

Most loudspeakers use bass reflex cabinets... An acoustic "short circuit" happens below the tuning frequency, which means that such speaker won't produce deeper bass no matter how much you try to equalize. Moving air waves at low frequencies requires a lot of energy which in turn may be demanding for the woofer, amplifier, etc. I guess most of the distortion is actually caused by the woofer exceeding its linear area of operation (leads to compression). And there's room acoustics to worry about as well. So its a bit different story altogether.